<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
   
   <meta name="description" content="string operations">
    
    <meta name="author" content="John S. Urban" >
    <link rel="icon" href="../favicon.png">

    <title>rotate13 &ndash; M_strings</title>

    <link href="../css/bootstrap.min.css" rel="stylesheet">
    <link href="../css/pygments.css" rel="stylesheet">
    <link href="../css/font-awesome.min.css" rel="stylesheet">
    <link href="../css/local.css" rel="stylesheet">
    
    <link  href="../tipuesearch/tipuesearch.css" rel="stylesheet">
    
    

    <!-- HTML5 shim and Respond.js for IE8 support of HTML5 elements and media queries -->
    <!--[if lt IE 9]>
      <script src="https://oss.maxcdn.com/html5shiv/3.7.2/html5shiv.min.js"></script>
      <script src="https://oss.maxcdn.com/respond/1.4.2/respond.min.js"></script>
    <![endif]-->
    
    <script src="../js/jquery-2.1.3.min.js"></script>
    <script src="../js/svg-pan-zoom.min.js"></script>

  </head>

  <body>

    <!-- Fixed navbar -->
    <nav class="navbar navbar-inverse navbar-fixed-top">
      <div class="container">
        <div class="navbar-header">
          <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar" aria-expanded="false" aria-controls="navbar">
            <span class="sr-only">Toggle navigation</span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
          </button>
          <a class="navbar-brand" href="../index.html">M_strings </a>
        </div>
        <div id="navbar" class="navbar-collapse collapse">
          <ul class="nav navbar-nav">
        
            <li class="dropdown hidden-xs visible-sm visible-md hidden-lg">
              <a href="#" class="dropdown-toggle"
              data-toggle="dropdown" role="button"
              aria-haspopup="true"
     aria-expanded="false">Contents <span class="caret"></span></a>
        <ul class="dropdown-menu">
          
              
            <li><a href="../lists/files.html">Source Files</a></li>
        
        
        
            <li><a href="../lists/modules.html">Modules</a></li>
        
            
                                
            <li><a href="../lists/procedures.html">Procedures</a></li>
        
               
            <li><a href="../lists/types.html">Derived Types</a></li>
        
        
            </ul>
            </li>


<li class="visible-xs hidden-sm visible-lg"><a href="../lists/files.html">Source Files</a></li>



<li class="visible-xs hidden-sm visible-lg"><a href="../lists/modules.html">Modules</a></li>



<li class="visible-xs hidden-sm visible-lg"><a href="../lists/procedures.html">Procedures</a></li>

                             
<li class="visible-xs hidden-sm visible-lg"><a href="../lists/types.html">Derived Types</a></li>


          </ul>
        
        <form action="../search.html" class="navbar-form navbar-right" role="search">
        <div class="form-group">
          <input type="text" class="form-control" placeholder="Search" name="q" id="tipue_search_input" autocomplete="off" required>
        </div>
<!--
        <button type="submit" class="btn btn-default">Submit</button>
-->
        </form>
        
        </div><!--/.nav-collapse -->
      </div>
    </nav>

    <div class="container">
    
  
  <div class="row">
    <h1>rotate13
      <small>Function</small>
    
    </h1>
    
<div class="row">
  <div class="col-lg-12">
<div class="well well-sm">
  <ul class="list-inline" style="margin-bottom:0px;display:inline">
     
     
     
     
    
    
     <li><i class="fa fa-list-ol"></i>
       <a data-toggle="tooltip"
    data-placement="bottom" data-html="true"
    title=" 0.7% of total for procedures.">18 statements</a>
     </li> 
     
     
     
    <li><i class="fa fa-code"></i><a href="../src/M_strings.f90"> Source File</a></li>
     
     
  </ul>
  <ol class="breadcrumb in-well text-right">
  
    
     <li><a href='../sourcefile/m_strings.f90.html'>M_strings.f90</a></li>
    
     <li><a href='../module/m_strings.html'>M_strings</a></li>
    
  
     <li class="active">rotate13</li>
  </ol>
</div>
</div>
</div>
<script>
  $(function () {
  $('[data-toggle="tooltip"]').tooltip()
  })
</script>

  </div>
  
  <div class="row">
    <div class="col-md-3 hidden-xs hidden-sm visible-md visible-lg">
    
<div id="sidebar">
  
<h3>Contents</h3>
 



<div class="panel panel-primary">
  <div class="panel-heading text-left"><h3 class="panel-title"><a data-toggle="collapse" href="#vars-0">Variables</a></h3></div>
  <div id="vars-0" class="panel-collapse collapse">
    <div class="list-group">
      
      <a class="list-group-item" href="../proc/rotate13.html#variable-i~15">i</a>
      
      <a class="list-group-item" href="../proc/rotate13.html#variable-itemp">itemp</a>
      
    </div>
  </div>
</div>




















<div class="panel panel-primary">
  <div class="panel-heading text-left"><h3 class="panel-title">Source Code</h3></div>
  <div class="list-group">
    <a class="list-group-item" href="../proc/rotate13.html#src">rotate13</a>
  </div>
</div>



</div>

    </div>
    
    <div class="col-md-9" id='text'>
    <h2>
public function rotate13(input)
    
    
   
</h2>
    
  


    
    <h2 id="name">NAME</h2>
<div class="codehilite"><pre><span></span><code><span class="n">rotate13</span><span class="p">(</span><span class="mi">3</span><span class="n">f</span><span class="p">)</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="o">[</span><span class="n">M_strings</span><span class="o">]</span><span class="w"> </span><span class="n">apply</span><span class="w"> </span><span class="n">trivial</span><span class="w"> </span><span class="n">ROT13</span><span class="w"> </span><span class="n">encryption</span><span class="w"> </span><span class="k">to</span><span class="w"> </span><span class="n">a</span><span class="w"> </span><span class="n">string</span><span class="w"></span>
<span class="p">(</span><span class="nl">LICENSE</span><span class="p">:</span><span class="n">PD</span><span class="p">)</span><span class="w"></span>
</code></pre></div>

<h2 id="synopsis">SYNOPSIS</h2>
<div class="codehilite"><pre><span></span><code>rotate13(input) result(output)

 character(len=*),intent(in) :: input
 character(len=len(input))   :: output
</code></pre></div>

<h2 id="description">DESCRIPTION</h2>
<div class="codehilite"><pre><span></span><code><span class="n">ROT13</span> <span class="p">(</span><span class="s2">&quot;rotate by 13 places&quot;</span><span class="p">,</span> <span class="n">sometimes</span> <span class="n">hyphenated</span> <span class="n">ROT</span><span class="o">-</span><span class="mi">13</span><span class="p">)</span> <span class="k">is</span> <span class="n">a</span> <span class="n">simple</span>
<span class="n">letter</span> <span class="n">substitution</span> <span class="n">cipher</span> <span class="n">that</span> <span class="n">replaces</span> <span class="n">a</span> <span class="n">letter</span> <span class="n">with</span> <span class="n">the</span> <span class="mi">13</span><span class="n">th</span> <span class="n">letter</span>
<span class="n">after</span> <span class="n">it</span> <span class="ow">in</span> <span class="n">the</span> <span class="n">alphabet</span><span class="p">;</span> <span class="n">wrapping</span> <span class="n">around</span> <span class="k">if</span> <span class="n">necessary</span><span class="o">.</span>

<span class="n">The</span> <span class="n">transformation</span> <span class="n">can</span> <span class="n">be</span> <span class="n">done</span> <span class="n">using</span> <span class="n">a</span> <span class="n">lookup</span> <span class="n">table</span><span class="p">,</span> <span class="n">such</span> <span class="k">as</span> <span class="n">the</span>
<span class="n">following</span><span class="p">:</span>

   <span class="n">Input</span>  <span class="n">ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz</span>
   <span class="n">Output</span> <span class="n">NOPQRSTUVWXYZABCDEFGHIJKLMnopqrstuvwxyzabcdefghijklm</span>

<span class="n">ROT13</span> <span class="k">is</span> <span class="n">used</span> <span class="ow">in</span> <span class="n">online</span> <span class="n">forums</span> <span class="k">as</span> <span class="n">a</span> <span class="n">means</span> <span class="n">of</span> <span class="n">hiding</span> <span class="n">spoilers</span><span class="p">,</span>
<span class="n">punchlines</span><span class="p">,</span> <span class="n">puzzle</span> <span class="n">solutions</span><span class="p">,</span> <span class="ow">and</span> <span class="n">offensive</span> <span class="n">materials</span> <span class="n">from</span> <span class="n">the</span> <span class="n">casual</span>
<span class="n">glance</span><span class="o">.</span> <span class="n">ROT13</span> <span class="n">has</span> <span class="n">inspired</span> <span class="n">a</span> <span class="n">variety</span> <span class="n">of</span> <span class="n">letter</span> <span class="ow">and</span> <span class="n">word</span> <span class="n">games</span> <span class="n">on</span><span class="o">-</span><span class="n">line</span><span class="p">,</span>
<span class="ow">and</span> <span class="k">is</span> <span class="n">frequently</span> <span class="n">mentioned</span> <span class="ow">in</span> <span class="n">newsgroup</span> <span class="n">conversations</span><span class="o">.</span>

<span class="n">The</span> <span class="n">algorithm</span> <span class="n">provides</span> <span class="n">virtually</span> <span class="n">no</span> <span class="n">cryptographic</span> <span class="n">security</span><span class="p">,</span> <span class="ow">and</span> <span class="k">is</span>
<span class="n">often</span> <span class="n">cited</span> <span class="k">as</span> <span class="n">a</span> <span class="n">canonical</span> <span class="n">example</span> <span class="n">of</span> <span class="n">weak</span> <span class="n">encryption</span><span class="o">.</span>

<span class="n">ROT13</span> <span class="k">is</span> <span class="n">a</span> <span class="n">special</span> <span class="n">case</span> <span class="n">of</span> <span class="n">the</span> <span class="n">Caesar</span> <span class="n">cipher</span> <span class="n">which</span> <span class="n">was</span> <span class="n">developed</span> <span class="ow">in</span>
<span class="n">ancient</span> <span class="n">Rome</span><span class="o">.</span>

<span class="n">ALGORITHM</span>

<span class="n">Applying</span> <span class="n">ROT13</span> <span class="n">to</span> <span class="n">a</span> <span class="n">piece</span> <span class="n">of</span> <span class="n">text</span> <span class="n">merely</span> <span class="n">requires</span> <span class="n">examining</span> <span class="n">its</span>
<span class="n">alphabetic</span> <span class="n">characters</span> <span class="ow">and</span> <span class="n">replacing</span> <span class="n">each</span> <span class="n">one</span> <span class="n">by</span> <span class="n">the</span> <span class="n">letter</span> <span class="mi">13</span> <span class="n">places</span>
<span class="n">further</span> <span class="n">along</span> <span class="ow">in</span> <span class="n">the</span> <span class="n">alphabet</span><span class="p">,</span> <span class="n">wrapping</span> <span class="n">back</span> <span class="n">to</span> <span class="n">the</span> <span class="n">beginning</span> <span class="k">if</span>
<span class="n">necessary</span><span class="o">.</span> <span class="n">A</span> <span class="n">becomes</span> <span class="n">N</span><span class="p">,</span> <span class="n">B</span> <span class="n">becomes</span> <span class="n">O</span><span class="p">,</span> <span class="ow">and</span> <span class="n">so</span> <span class="n">on</span> <span class="n">up</span> <span class="n">to</span> <span class="n">M</span><span class="p">,</span> <span class="n">which</span> <span class="n">becomes</span>
<span class="n">Z</span><span class="p">,</span> <span class="n">then</span> <span class="n">the</span> <span class="n">sequence</span> <span class="n">continues</span> <span class="n">at</span> <span class="n">the</span> <span class="n">beginning</span> <span class="n">of</span> <span class="n">the</span> <span class="n">alphabet</span><span class="p">:</span> <span class="n">N</span>
<span class="n">becomes</span> <span class="n">A</span><span class="p">,</span> <span class="n">O</span> <span class="n">becomes</span> <span class="n">B</span><span class="p">,</span> <span class="ow">and</span> <span class="n">so</span> <span class="n">on</span> <span class="n">to</span> <span class="n">Z</span><span class="p">,</span> <span class="n">which</span> <span class="n">becomes</span> <span class="n">M</span><span class="o">.</span> <span class="n">Only</span> <span class="n">those</span>
<span class="n">letters</span> <span class="n">which</span> <span class="n">occur</span> <span class="ow">in</span> <span class="n">the</span> <span class="n">English</span> <span class="n">alphabet</span> <span class="n">are</span> <span class="n">affected</span><span class="p">;</span> <span class="n">numbers</span><span class="p">,</span>
<span class="n">symbols</span><span class="p">,</span> <span class="n">whitespace</span><span class="p">,</span> <span class="ow">and</span> <span class="n">all</span> <span class="n">other</span> <span class="n">characters</span> <span class="n">are</span> <span class="n">left</span> <span class="n">unchanged</span><span class="o">.</span>

<span class="n">SAME</span> <span class="n">ALGORITHM</span> <span class="n">FOR</span> <span class="n">ENCODING</span> <span class="n">AND</span> <span class="n">DECODING</span>

<span class="n">Because</span> <span class="n">there</span> <span class="n">are</span> <span class="mi">26</span> <span class="n">letters</span> <span class="ow">in</span> <span class="n">the</span> <span class="n">English</span> <span class="n">alphabet</span> <span class="ow">and</span> <span class="mi">26</span> <span class="o">=</span> <span class="mi">2</span> <span class="n">x</span> <span class="mi">13</span><span class="p">,</span>
<span class="n">the</span> <span class="n">ROT13</span> <span class="n">function</span> <span class="k">is</span> <span class="n">its</span> <span class="n">own</span> <span class="n">inverse</span><span class="p">:</span> <span class="n">so</span> <span class="n">the</span> <span class="n">same</span> <span class="n">action</span> <span class="n">can</span> <span class="n">be</span> <span class="n">used</span>
<span class="k">for</span> <span class="n">encoding</span> <span class="ow">and</span> <span class="n">decoding</span><span class="o">.</span> <span class="n">In</span> <span class="n">other</span> <span class="n">words</span><span class="p">,</span> <span class="n">two</span> <span class="n">successive</span> <span class="n">applications</span>
<span class="n">of</span> <span class="n">ROT13</span> <span class="n">restore</span> <span class="n">the</span> <span class="n">original</span> <span class="n">text</span> <span class="p">(</span><span class="ow">in</span> <span class="n">mathematics</span><span class="p">,</span> <span class="n">this</span> <span class="k">is</span> <span class="n">sometimes</span>
<span class="n">called</span> <span class="n">an</span> <span class="n">involution</span><span class="p">;</span> <span class="ow">in</span> <span class="n">cryptography</span><span class="p">,</span> <span class="n">a</span> <span class="n">reciprocal</span> <span class="n">cipher</span><span class="p">)</span><span class="o">.</span>

<span class="n">TRIVIAL</span> <span class="n">SECURITY</span>

<span class="n">The</span> <span class="n">use</span> <span class="n">of</span> <span class="n">a</span> <span class="n">constant</span> <span class="n">shift</span> <span class="n">means</span> <span class="n">that</span> <span class="n">the</span> <span class="n">encryption</span> <span class="n">effectively</span>
<span class="n">has</span> <span class="n">no</span> <span class="n">key</span><span class="p">,</span> <span class="ow">and</span> <span class="n">decryption</span> <span class="n">requires</span> <span class="n">no</span> <span class="n">more</span> <span class="n">knowledge</span> <span class="n">than</span> <span class="n">the</span> <span class="n">fact</span>
<span class="n">that</span> <span class="n">ROT13</span> <span class="k">is</span> <span class="ow">in</span> <span class="n">use</span><span class="o">.</span> <span class="n">Even</span> <span class="n">without</span> <span class="n">this</span> <span class="n">knowledge</span><span class="p">,</span> <span class="n">the</span> <span class="n">algorithm</span> <span class="k">is</span>
<span class="n">easily</span> <span class="n">broken</span> <span class="n">through</span> <span class="n">frequency</span> <span class="n">analysis</span><span class="o">.</span>

<span class="n">In</span> <span class="n">encrypted</span> <span class="n">normal</span> <span class="n">English</span><span class="o">-</span><span class="n">language</span> <span class="n">text</span> <span class="n">of</span> <span class="n">any</span> <span class="n">significant</span> <span class="n">size</span><span class="p">,</span>
<span class="n">ROT13</span> <span class="k">is</span> <span class="n">recognizable</span> <span class="n">from</span> <span class="n">some</span> <span class="n">letter</span><span class="o">/</span><span class="n">word</span> <span class="n">patterns</span><span class="o">.</span> <span class="n">The</span> <span class="n">words</span> <span class="s2">&quot;n&quot;</span><span class="p">,</span>
<span class="s2">&quot;V&quot;</span> <span class="p">(</span><span class="n">capitalized</span> <span class="n">only</span><span class="p">),</span> <span class="ow">and</span> <span class="s2">&quot;gur&quot;</span> <span class="p">(</span><span class="n">ROT13</span> <span class="k">for</span> <span class="s2">&quot;a&quot;</span><span class="p">,</span> <span class="s2">&quot;I&quot;</span><span class="p">,</span> <span class="ow">and</span> <span class="s2">&quot;the&quot;</span><span class="p">),</span>
<span class="ow">and</span> <span class="n">words</span> <span class="n">ending</span> <span class="ow">in</span> <span class="s2">&quot;yl&quot;</span> <span class="p">(</span><span class="s2">&quot;ly&quot;</span><span class="p">)</span> <span class="n">are</span> <span class="n">examples</span><span class="o">.</span>
</code></pre></div>

<h2 id="references">REFERENCES</h2>
<div class="codehilite"><pre><span></span><code>Wikipedia, the free encyclopedia
</code></pre></div>

<h2 id="example">EXAMPLE</h2>
<p>Sample program</p>
<div class="codehilite"><pre><span></span><code><span class="nv">program</span> <span class="nv">demo_rotate13</span>
<span class="nv">use</span> <span class="nv">M_strings</span>, <span class="nv">only</span> : <span class="nv">rotate13</span>
<span class="nv">implicit</span> <span class="nv">none</span>
<span class="nv">character</span><span class="ss">(</span><span class="nv">len</span><span class="o">=</span><span class="mi">256</span><span class="ss">)</span> :: <span class="nv">line</span>
<span class="nv">integer</span>            :: <span class="nv">ios</span>
<span class="k">do</span>
   <span class="nv">read</span><span class="ss">(</span><span class="o">*</span>,<span class="s1">&#39;</span><span class="s">(a)</span><span class="s1">&#39;</span>,<span class="nv">iostat</span><span class="o">=</span><span class="nv">ios</span><span class="ss">)</span><span class="nv">line</span>
   <span class="k">if</span><span class="ss">(</span><span class="nv">ios</span>.<span class="nv">ne</span>.<span class="mi">0</span><span class="ss">)</span><span class="k">exit</span>
   <span class="nv">write</span><span class="ss">(</span><span class="o">*</span>,<span class="s1">&#39;</span><span class="s">(a)</span><span class="s1">&#39;</span><span class="ss">)</span><span class="nv">rotate13</span><span class="ss">(</span><span class="nv">line</span><span class="ss">)</span>
<span class="nv">enddo</span>
<span class="k">end</span> <span class="nv">program</span> <span class="nv">demo_rotate13</span>
</code></pre></div>

<p>Sample usage:</p>
<div class="codehilite"><pre><span></span><code>demo_rotate13
United we stand, divided we fall.
Havgrq jr fgnaq, qvivqrq jr snyy.
</code></pre></div>

<h2 id="author">AUTHOR</h2>
<div class="codehilite"><pre><span></span><code>John S. Urban
</code></pre></div>

<h2 id="license">LICENSE</h2>
<div class="codehilite"><pre><span></span><code>Public Domain
</code></pre></div>
    

    <h3>Arguments</h3>
    
      
<table class="table table-striped varlist">
<thead><tr><th>Type</th>
<th>Intent</th><th>Optional</th>
<th>Attributes</th><th></th><th>Name</th><th></th></thead>



<tbody>

  
  
  
  
<tr>
  
  <td><span class="anchor" id="variable-input"></span>character(len=*),</td>
  <td>intent(in)</td>
  <td></td>
  
  <td></td><td>::</td>
  <td><strong>input</strong></td><td></td>
  
</tr>

</tbody>
</table>

    
    
    
    
    
    
    
   <h3>Return Value <small><span class="anchor" id="variable-rotate13"></span>character(len=len(input))
  </small></h3>
    
    
    
    
     
    <br>

    <section class="visible-xs visible-sm hidden-md">
      
<h3>Contents</h3>
 



<div class="panel panel-primary">
  <div class="panel-heading text-left"><h3 class="panel-title"><a data-toggle="collapse" href="#vars-1">Variables</a></h3></div>
  <div id="vars-1" class="panel-collapse collapse">
    <div class="list-group">
      
      <a class="list-group-item" href="../proc/rotate13.html#variable-i~15">i</a>
      
      <a class="list-group-item" href="../proc/rotate13.html#variable-itemp">itemp</a>
      
    </div>
  </div>
</div>




















<div class="panel panel-primary">
  <div class="panel-heading text-left"><h3 class="panel-title">Source Code</h3></div>
  <div class="list-group">
    <a class="list-group-item" href="../proc/rotate13.html#src">rotate13</a>
  </div>
</div>



    </section>
    <br class="visible-xs visible-sm hidden-md">

    

    
    <section>    
      <h2>Variables</h2>
    
<table class="table table-striped varlist">
<thead><tr><th>Type</th><th>Visibility</th>

<th>Attributes</th><th></th><th>Name</th><th></th><th>Initial</th><th></th></thead>



<tbody>

  
  
  
  
<tr>
  
  <td><span class="anchor" id="variable-i~15"></span>integer,</td>
  
  <td>public</td>
  <td></td><td>::</td>
  <td><strong>i</strong></td><td></td><td></td><td></td>
  
</tr>

  
  
  
  
<tr>
  
  <td><span class="anchor" id="variable-itemp"></span>integer,</td>
  
  <td>public</td>
  <td></td><td>::</td>
  <td><strong>itemp</strong></td><td></td><td></td><td></td>
  
</tr>

</tbody>
</table>

    </section>
    <br>
    
    
    
    
    

    
    
    
    
    


    
    
    
    <section>
    <h2><span class="anchor" id="src"></span>Source Code</h2>
    <div class="highlight"><pre><span></span><span class="k">function </span><span class="n">rotate13</span> <span class="p">(</span><span class="n">input</span><span class="p">)</span>
<span class="k">implicit none</span>

<span class="c">! ident_18=&quot;@(#)M_strings::rotate13(3f): converts a character to its ROT13 equivalent, which is a trivial encryption.&quot;</span>

<span class="kt">character</span><span class="p">(</span><span class="nb">len</span><span class="o">=*</span><span class="p">),</span><span class="k">intent</span><span class="p">(</span><span class="n">in</span><span class="p">)</span> <span class="kd">::</span> <span class="n">input</span>
<span class="kt">character</span><span class="p">(</span><span class="nb">len</span><span class="o">=</span><span class="nb">len</span><span class="p">(</span><span class="n">input</span><span class="p">))</span>   <span class="kd">::</span> <span class="n">rotate13</span>
<span class="kt">integer</span>                     <span class="kd">::</span> <span class="n">itemp</span>
<span class="kt">integer</span>                     <span class="kd">::</span> <span class="n">i</span>
   <span class="n">rotate13</span><span class="o">=</span><span class="s1">&#39; &#39;</span>
   <span class="k">do </span><span class="n">i</span><span class="o">=</span><span class="mi">1</span><span class="p">,</span><span class="nb">len_trim</span><span class="p">(</span><span class="n">input</span><span class="p">)</span>
      <span class="n">itemp</span> <span class="o">=</span> <span class="nb">iachar</span><span class="p">(</span><span class="n">input</span><span class="p">(</span><span class="n">i</span><span class="p">:</span><span class="n">i</span><span class="p">))</span>
      <span class="k">select case</span><span class="p">(</span><span class="n">itemp</span><span class="p">)</span>
       <span class="k">case</span><span class="p">(</span><span class="mi">65</span><span class="p">:</span><span class="mi">77</span><span class="p">,</span><span class="mi">97</span><span class="p">:</span><span class="mi">109</span><span class="p">)</span>
         <span class="n">itemp</span> <span class="o">=</span> <span class="n">itemp</span> <span class="o">+</span> <span class="mi">13</span>
       <span class="k">case</span><span class="p">(</span><span class="mi">78</span><span class="p">:</span><span class="mi">90</span><span class="p">,</span><span class="mi">110</span><span class="p">:</span><span class="mi">122</span><span class="p">)</span>
         <span class="n">itemp</span> <span class="o">=</span> <span class="n">itemp</span> <span class="o">-</span> <span class="mi">13</span>
      <span class="k">end select</span>
<span class="k">      </span><span class="n">rotate13</span><span class="p">(</span><span class="n">i</span><span class="p">:</span><span class="n">i</span><span class="p">)</span> <span class="o">=</span> <span class="nb">char</span> <span class="p">(</span> <span class="n">itemp</span> <span class="p">)</span>
   <span class="k">enddo</span>

<span class="k">end function </span><span class="n">rotate13</span>
</pre></div>

    </section>
    <br>
    
    
    </div>
  </div>


    <hr>    
    </div> <!-- /container -->
    <footer>
      <div class="container">
      <div class="row">
        <div class="col-xs-6 col-md-4"><p>&copy; 2022 
                                          </p></div>
        <div class="col-xs-6 col-md-4 col-md-push-4">
          <p class="text-right">
            Documentation generated by 
            <a href="https://github.com/cmacmackin/ford">FORD</a>
             on 2022-01-16 22:32  
          </p>
        </div>
        <div class="col-xs-12 col-md-4 col-md-pull-4"><p class="text-center"> M_strings was developed by John S. Urban</p></div>
      </div>
      <br>
      </div> <!-- /container -->    
    </footer>

    <!-- Bootstrap core JavaScript
    ================================================== -->
    <!-- Placed at the end of the document so the pages load faster -->
<!--
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
-->
    <script src="../js/bootstrap.min.js"></script>
    <!-- IE10 viewport hack for Surface/desktop Windows 8 bug -->
    <script src="../js/ie10-viewport-bug-workaround.js"></script>

    <!-- MathJax JavaScript
    ================================================== -->
    <!-- Placed at the end of the document so the pages load faster -->
    <script type="text/x-mathjax-config">
      MathJax.Hub.Config({
        TeX: { extensions: ['AMSmath.js','AMSsymbols.js','noErrors.js','noUndefined.js'], equationNumbers: { autoNumber: 'AMS' } },
        jax: ['input/TeX','input/MathML','output/HTML-CSS'],
        extensions: ['tex2jax.js','mml2jax.js','MathMenu.js','MathZoom.js']
      });
    </script>
    
    <script src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
    
    
    <script src="../tipuesearch/tipuesearch_content.js"></script>
    <script src="../tipuesearch/tipuesearch_set.js"></script>
    <script src="../tipuesearch/tipuesearch.js"></script>
    
    
  </body>
</html>